In vehicles, manual gearboxes are used for changing the gear ratio between a traction motor and driven wheels. Shifting the manual gearbox takes place, for example, when the speed of the vehicle increases.
While multigear manual gearboxes are customary for vehicles with internal combustion engines, in manual gearboxes for vehicles with electric motors, variants have instead come into use which include only a small number of gears. Thus, it is quite common for this type of manual gearbox to include only two gears. In addition, in manual gearboxes for vehicles with electric motors, the motor characteristic of the electric motor as a traction motor may be addressed. Due to the motor characteristic, vehicles with electric motors have different criteria for a manual gearbox than vehicles with internal combustion engines, for example.
The publication DE 10 2011 080 454 A1 relates to a vehicle with a hybrid drive. The vehicle includes an internal combustion engine and an electric motor. A gearbox structure is connected between the internal combustion engine and the electric motor, and includes a clutch device and freewheel clutch, which in terms of gearing are situated in parallel to one another. Different drive modes of the vehicle are possible with this gearbox structure.
The publication DE 10 2012 216 132 A1 provides a wheel hub drive for driving a wheel of a motor vehicle, with a drive train that includes an electric drive motor and a gearbox. The gearbox is designed as a manually or automatically shiftable gearbox for torque conversion with at least two gears.
The publication DE 10 2012 015 863 A1 provides a stepped gearbox for a motor vehicle, including a gearbox input that is connectable to a drive motor, and a gearbox output that is connectable to a driven axle of a motor vehicle, the stepped gearbox being designed for providing one first gear and one additional gear. A power transmission from the gearbox input to the gearbox output in the first gear takes place via a first clutch system (freewheel clutch). A power transmission in the additional gear takes place via a second clutch system (powershift clutch).
The publication AT 171 474 B, which constitutes the most proximate prior art, provides a variable-speed gearbox, all the gears of which are automatically shifted by centrifugal clutches, the gearwheels always remaining engaged by use of freewheel clutches. The variable-speed gearbox includes a centrifugal multi-plate clutch, whereby with increasing engine speed, a power flow passes from a main gearbox shaft via the centrifugal multi-plate clutch to a driven shaft. As the engine speed further increases, the power flow passes via a second centrifugal multi-plate clutch, the driven shaft being directly connected to the main gearbox shaft.